Paratrimerins J–Y, Dimeric Coumarins Isolated from the Stems of Paramignya trimera

Abstract

Paratrimerins J−Y (1−13 and 16−18), new dimeric coumarins, were obtained from the EtOH(aq) extract of the stems of Paramignya trimera (Rutaceae) utilizing LC/MS guided isolation. The structures of the dimeric coumarins were elucidated based on 1D/2D NMR spectroscopic and HR-ESIMS data analyses. The absolute configurations of paratrimerins J−Y along with those of two known dimers paratrimerins A ( 14) and B (15) were established on the basis of the experimental and simulated ECD data. In addition, the absolute configurations of the sugar units of paratrimerins A, B, and J−V (1−15) were confirmed by LC/MS analysis on L-cysteine methyl ester and phenyl isothiocyanate derivatives. The variety of the absolute configurations of the dimeric diastereomers 1−15 highlighted a diversity in stereochemical outcomes following a Diels− Alder biosynthesis in P. trimera. With regard to P. trimera being a recently emerging medicinal resource for liver cancer, the dimers 1−18 were evaluated for cytotoxicity against a wide panel of human cancer cell lines. Paratrimerin W ( 16) was cytotoxic toward Huh7 hepatocellular carcinoma, HT1080 fibrosarcoma, and HT29 colorectal cancer cells with IC 50 values of 14.9, 18.4, and 22.5 μM, respectively.

Chemoreactive 2,5-Diketopiperazines from a Penicillium sp., Structure Revision of Reported Analogues and Proposed Facile Transformation Pathways

“…ECD Calcualtion. 56,57 Geometry, frequency, and ECD calculations were performed using DFT and TD-DFT with Gaussian 16 on NIH High Performance Computer Biowulf. Specifically, for compound 1, input conformers were optimized using DFT with B3LYP/6-31G(d).…”

Computational methods and points for attention in absolute configuration determination

“…Electronic circular dichroism (ECD) spectra have been used for AC determination since the 1960s. ECD was originally known more simply as CD, and, more recently, many reports use the term ECD for AC assignment (Guo et al, 2020;Zhang et al, 2021b;Kim et al, 2021;Nhoek et al, 2021;Quan et al, 2021). As mentioned above, a detailed conformational search should first be performed (Mazzeo et al, 2014).…”

Studies on hepatoprotective effects of Vietnamese medicinal plants

“…A phytochemical study of P. trimera roots (Xáo tam phân) revealed the presence of a variety of coumarins and coumarin glycosides, including simple coumarins (ostruthin, ninhvanins A-B, 6-(6-hydroxy-3,7-dimethylocta-2,7-dienyl)-7-hydroxycoumarin, esculetin, and scopoletin) [70,71] and biscoumarin monoterpene glycosides such as paratrimerins A-B and paratrimerins J-Y [72,73]. Both the methanol extract and the water decoction of P. trimera roots showed hepatoprotective activities in PAR-induced liver damage mice.…”